1. Field of the Invention
The present invention relates to "rear entry" alpine ski boots comprising an upper having front and rear portions which surround the lower leg of the skier. More particularly, the invention relates to "rear entry" alpine ski boots comprising means for permitting the entry ahd removal of the foot to and from the boot, as well as for controlling the support for the lower leg of the skier during skiiing.
2. Background Information
Rear entry type alpine ski boots generally comprise a shell base and an upper having front and rear portions. The rear portion is displaceable relative to the shell base and/or with respect to the front portion between a maintenance position in which the rear portion is positioned against the lower leg of the skier, and an open position which allows for disengagement of the foot of the skier from the boot or the introduction of the foot of the skier into the boot.
Thus, for example, U.S. Pat. No. 4,095,356 describes a ski boot which comprises an upper comprising latches for closing the upper on the lower leg of the skier. The upper further comprises a front portion, journalled around a journal element on the shell base. The front portion is provided with lateral extensions which extend on each side of the shell base. These extensions each comprise another journal axis on which the rear portion of the upper is journalled. In this type of boot, the control of the frontward and rearward pressure of the lower leg of the skier on the upper is achieved by means of a single front portion of the upper, associated with shock absorption elements. Because this control occurs essentially at the front portion of the upper, all of the rearward pressure exerted by the lower leg of the skier on the upper is supported by the closure latches of the upper.
Other rear-entry type boots, of the type described in U.S. Pat. No. 4,222,184, comprise a rear portion of the upper which pivots with respect to the shell base at the level of the heel of the boot around a first journal axis. This first journal axis is independent of the front portion of the upper. The front portion of the upper is also journalled around the shell base, but around another journal axis. In this type of boot, the control of the support forces is achieved again at the level of the front portion of the upper, which is provided with an extension extending to the front of the leg of the skier, and which is also provided with a collar adapted to maintain the extension against the leg. In this case, the rear portion of the upper serves only as a manipulation lever for holding down the foot inside the boot. This boot does not permit resistance to rearward pressure of the lower leg of the skier by means of the rear portion of the upper.